Mary Leakey, one of the most dedicated and respected paleontologists in the world, was the wife and partner of Louis Leakey and mother of Richard Leakey. Unlike them, however, she was more interested in stones than bones. Though she was the discoverer of Zinjanthropus, one of the most important of the early hominid skulls; thousands of other fossilized hominid bones; and the little hominid footprints at Laetoli, more than three million years old, she was looking for artifacts when she found them. She believed that it was man's early tools and the insights they gave about early man that were the keys to understanding what man was like at various stages of evolution. While Louis was looking for bones, Mary was often tracing and recording the art of the rock shelters she discovered or looking for handaxes.

The daughter of a well-known artist who had an interest in archaeology, she was also a descendant of John Frere, an 18th century British archaeologist, who reported on extinct animals sixty years before Darwin published his theory of evolution. Though she had only two or three years of traditional schooling, she traveled through Europe with her parents, crawling through pre-historic caves in France; collecting flint tools, end scrapers, and bone points among the spoil heaps of Peyrony's excavations in France; and eventually working on excavations in England herself. It was her artistic talent which brought her to the attention of well-known archaeologists, including Louis Leakey, who needed someone with background in archaeological excavation who could also illustrate.

She candidly shares the personal details of their relationship throughout the nearly forty years of their marriage, during which time they raised three sons, all of them eventually making discoveries of the own, with Richard making more discoveries than both of his parents combined. Generous in crediting other researchers for their contributions, and genuinely curious and hard-working, Mary betrays none of the ego and competitive sense here which seem to dominate this research field. In fact, it is only when Donald Johanson, working in Ethiopia, uses her discovery of a jawbone 1000 miles away to draw what she considers erroneous conclusions about his much more complete (and quite different) Lucy skeleton that we see her ferocious temper, not out of jealousy but because she believed his book to be "lightweight," inaccurate, and misleading in its conclusions. Her own autobiography, by contrast, is always painfully honest, carefully considered, and modest in its assessment of her own contributions, a fascinating story of a woman who marched to her own drumbeat.